U.S. Pat. No. 3,671,048 discloses a lip type seal including a non-woven mat in a sealing lip. The mat is fabricated of randomly disposed interconnected fibers composed of a low friction polymer impregnated with elastomeric material.
U.S. Pat. No. 3,894,742 is concerned with a flexible, resilient, deterioration resistant seal that is capable of withstanding high temperatures and pressures. The seal is comprised of an inner core around which an inner and outer cover strip composed of thin metallic foil is spirally wound so as to enclose the entire core.
U.S. Pat. No. 4,917,302 describes a seal that includes a plurality of rectangular-shaped wafers stacked next to one another and preloaded in the axial direction to minimize leakage between wafers. The wafers are laterally preloaded to maintain sealing contact along the wafer faces which engage the adjacent wall.
U.S. Patent Ser. No. 441,672 which was filed by the NASA Administrator on Nov. 27, 1989, and issued as U.S. Pat. No 5,014,917 on 5/14/91, is directed to a high temperature, flexible, thermal barrier seal which comprises a high temperature outer sheathing with an inner core of densely packed, high temperature particles. The thermal barrier seal is preloaded lateral to its axis to maintain good sealing contact between the seal nose and the adjacent wall, as well as to ensure the seal follows the distorted sidewall.